That one was a bit of a major plot hole I found
After the first person shoots at the Borg with a Federation phaser, the Borg adapt to that first shot. The Borg drone relays the info to the hive and now all the Borg adapt to that first shot, then all of them with the second, third, fourth, etc, etc, etc.
The first encounter ends, now when the Borg interact with anyone from the Federation again … they’ve already adapted to phaser fire and a bunch of modulations from previous firings. So they adapt again and again. So after hundreds of encounters, Borg drones everywhere have pretty much adapted to a lot of different phaser modulations.
Unless phasers have an infinite number of modulations … after several years or decades of dealing with the Borg … the Borg would at one point be just completely immune to any and all phaser fire.
The impression I always got was Borg personal shielding could only “adapt” to one weapon type or modulation at a time, and so each encounter was kind of a soft reset.
Possibly post-Wolf 359 all Federation hand weapons come stock with a rotating frequency, or a unique pseudorandom phase variance and the first few shots get through before the local Borg adapt to that phaser.
Had the Borg stayed a threat the Federation would probably have developed a phaser analog to the transphasic torpedo, but I get why the shows never did that.
It’s a bit of an arms race of attrition, with the Federation having to eventually give up. Good thing they pissed off Janeway enough to just virus them and destroy most of their transwarp network.
What # Rule of Acquisition is that?
Oh, one of the high ones I’m pretty sure.